SOIL AND PLANT ANALYSIS (1+1)

Sub soil hardening /hard pan

The sub soil hard pan in red soils in due to illuviation of clay to the sub soil horizon coupled with cementing action of oxides of Fe, Al and calcium carbonate, which increases the bulk density to more than 1.8 Mg m-3. Further, the hard pan can also develop due to continuous cultivation of crops using heavy implements up to certain depth constantly. Besides, the higher exchangeable sodium content in black soil areas also results in compactness. All put together lowered the infiltration and percolation rates, nutrient movement and free air transport within the soils profile. It prevents root proliferation and limits the volume of soils available for nutrients uptake resulting in depleted, less fertile surface soil. Due to this, the contribution of sub soil fertility to crop growth is hampered.

Management
These soils are managed by adopting following practices
Ploughing the soil with chisel plough at 0.5m interval criss-cross at 0.5m depth once in 2-3 years.
Application of organics to improve the aggregation and soil structure so as to prevent further movement of clay to the lower layers.
Deep ploughing of the field during summer season to open up the sub soils.
Cultivating deep rooted crops like tapioca, cotton so as to encourage natural breaking of the hard pan.
Raising deep rooted semi perennial crops like mulberry, jasmine, match wood tree etc. can also help in opening up the sub surface hard pan.